Not sure what you mean by this??
Is it dangerous to burn something when H2 is around? Like Hindenburg.
No more dangerous (actually less dangerous) than to burn something when gasoline vapors are around. As to the Hindenberg, it turns out that the source of the original fire was NOT the lift gas hydrogen, but apparently a lightening strike that ignited the aluminum-doped painted fabric that comprised the external skin of the dirigible. It turns out that, once ignited, that paint mixture was more-or-less like solid rocket fuel. If you look at the pictures of the burning Hindenberg, you will see clouds of dense black smoke--hydrogen burns with an almost colorless and smokeless flame. Of course, the burning skin "did" eventually rupture the hydrogen cells and ignite the hydrogen.
"How complete is it to burn CO from H2?
Not sure what you mean by this??
What I'm trying to get at is whether the burning processor gets rid of all CO to get pure H2. If H2 is contaminated with CO, is there any bad effect from using CO-contaminated H2.